a statistical trendp < 0.001
In the retrospective analysis using data from a National Veterans Administration (VA) database [ 22 ], spatial information was recorded based on treatment facility, and using a statistical trend analysis, the risk of DE was higher in zip codes with an atmospheric pressure 1 standard deviation (SD) above the mean (IRR, 1.131; 95% CI, 1.129–1.133; p < 0.001).